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Biomedical subjects

J Ono

Publications and source records attributed to J Ono.

At least 19 recordsLinked to original sources
PubMed1999

Recovery of hearing after removal of a large jugular foramen schwannoma: report of two cases.

BACKGROUND: Although hearing loss is a common presenting symptom of jugular foramen schwannoma (JFS), recovery of hearing after tumor removal has rarely been reported. We report two cases of a large JFS presenting with severe hearing loss and recovering normal hearing after tumor removal. METHODS AND RESULTS: Two patients complaining of progressive hearing loss each proved to have a large JFS involving the posterior fossa. The hearing losses, which exceeded 90 dB, were not associated with dysfunction of the 9th, 10th, or 11th cranial nerves. Schwannomas were removed by a suboccipital retrosigmoid approach, preserving labyrinthine structures. The vestibulocochlear nerve, stretched and displaced rostrally by the tumor, was preserved with surrounding arachnoidal tissue. Soon after surgery, recovery of hearing began; normal hearing was restored within 3 months. CONCLUSIONS: In a case of JFS with severe hearing loss, normal hearing may be attainable by tumor removal using a retrosigmoid approach that preserves labyrinthine structures. The arachnoidal tissue separating the vestibulocochlear nerve from the schwannoma is important to hearing preservation.

Adult↗
PubMed1999

Remission of progressive multifocal leukoencephalopathy following highly active antiretroviral therapy in a patient with HIV infection.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease resulting from lytic infection of oligodendrocytes by the papovavirus JC (JCV). PML has also been recognized as an AIDS-defining illness. The incidence of PML has increased since 1987 and it occurs in up to 4% of patients with AIDS. To date, there is no treatment available for PML and it usually results in death within 3-6 months of diagnosis. However, there are some reports of remission of PML after antiretroviral therapy. We report a 12-year-old child with hemophilia B and developing AIDS with the onset of PML. With highly active antiretroviral therapy, PML subsided with an increase of CD4 count from 10 to 300/microl in spite of about 1.0 X 10(4) human immunodeficiency virus (HIV)-1-RNA copies. He has survived more than 1 year without specific therapy against JCV. Highly active antiretroviral therapy appears to have improved his prognosis in HIV-associated PML.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Ring chromosome 14 complicated with complex partial seizures and hypoplastic corpus callosum.

A Japanese male with mosaicism of ring chromosome 14 and chromosome 14 monosomy is described. He demonstrated the characteristic morphologic features of ring chromosome 14, in addition to mental retardation and epileptic seizures. Clusters of complex partial seizures, one of which originated in the left frontocentral region on electroencephalographic monitoring, were evident. His seizures responded to phenobarbital, and his mental and motor development was only mildly retarded. Magnetic resonance imaging revealed a hypoplastic corpus callosum, previously unknown in association with this syndrome.

Agenesis of Corpus Callosum↗
PubMed1999

Development of anti-influenza virus drugs I: improvement of oral absorption and in vivo anti-influenza activity of Stachyflin and its derivatives.

PURPOSE: Stachyflin and its derivatives which are active against the influenza virus in vitro, were studied to improve their reduced in vivo activity after oral administration by chemical modification and some vehicles. METHODS: The solubility was examined for different vehicles. The improvement of gastrointestinal absorption was evaluated by the plasma concentration after oral administration to mice or the in situ loop method with rats. The in vivo anti-influenza activity was examined using mice infected with the influenza virus and evaluated based on the virus titer in the lung by TCID50. RESULTS: PEG 400 showed the highest solubility of Stachyflin and its derivative among the vehicles studied. While no viral inhibition was found in the lung after oral administration of 0.5% HPMC suspension of Stachyflin, in vivo anti-influenza virus activity was found with the PEG 400 solution. The absorption of Stachyflin by PEG 400 showed about a fifty-fold increase in AUC compared with that of 0.5% HPMC suspension. Improving the oral absorption of Stachyflin led to an increase in the in vivo anti-influenza virus activity. When the Stachyflin derivative in PEG 4000 was administered orally, there was more enhancement of the oral absorption than with PEG 400. When the aqueous solution of the phosphate ester prodrugs of Stachyflin and its derivative was administered orally, the absorption of the parent compound was improved and in vivo anti-influenza virus activity was found. CONCLUSIONS: When Stachyflin and its derivatives were administered orally to mice with a solution in PEG and an aqueous solution of their phosphate ester, their oral absorption was improved and in vivo anti-influenza virus activity was observed.

Absorption↗
PubMed1999

Visual impairment and REP-1 gene mutations in Japanese choroideremia patients.

Choroideremia (CHM), an X-linked recessive hereditary disease, is an intractable chorioretinal dystrophy. The rate of disease progression of CHM reportedly shows considerable variability. A number of mutations involving the gene that codes for Rab escort protein-1 (REP-1) have been detected in CHM patients. We have analyzed REP-1 gene mutations of Japanese CHM patients. The present study was designed to investigate the clinical variability and the genotype to phenotype relationship in 15 Japanese CHM patients referred to the Department of Ophthalmology of Juntendo University Hospital. The clinical investigation of visual acuity, visual field, color vision and refraction revealed inter-individual variability. Mutation analyses of the REP-1 gene revealed 10 types of mutations in 13 patients from 11 families, including an insertion, small deletions, nonsense mutations and an A to CC mutation. In 13 CHM patients with detectable REP-1 gene mutations, no relationship of genotype to phenotype was detected. At present, we consider the REP-1 genotype to be an unreliable prognostic factor for counseling of CHM patients. In two patients from one family, no mutations were detected in coding regions of the REP-1 gene. These patients may have intron mutations of the REP-1 gene, not detectable by the techniques employed in this study, or other causative genes. Both were observed to have somewhat slower disease progression than the other 13 patients. More advanced analyses are necessary to answer questions regarding the genotype-phenotype relationship in CHM patients.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Ictal video-EEG recording of three partial seizures in a patient with the benign infantile convulsions associated with mild gastroenteritis.

PURPOSE: In infants, benign convulsions can be triggered by febrile illness or mild diarrhea such as Rotavirus gastroenteritis. The triggering mechanism of these convulsions is still unknown. In spite of several reports concerning clinical features, the ictal EEG recordings were rarely analyzed by a video-EEG monitoring system. To reveal a clue for the triggering mechanism of these convulsions, we analyzed the correlation of clinical manifestations and the EEG discharges during the ictal events and compared with previous reports. METHODS: The ictal EEG of a cluster of three afebrile convulsions associated with mild gastroenteritis was recorded by an EEG closed-circuit TV (EEG-CCTV) monitoring system in a 6-month-old healthy female infant. RESULTS: All seizures began as complex partial seizures (CPSs), which exhibited a motionless stare with or without leftward deviation of both eyes, and evolved to secondarily generalized tonic-clonic seizures (SGTCSs) for approximately 90 s. Each of three ictal discharges began from the right occipital, right centroparietotemporal, and left occipital regions, respectively. CONCLUSIONS: Although initiating sites of ictal discharges of benign infantile convulsions associated with mild gastroenteritis (BICE) were previously reported to be variable among patients, these results indicated that those differ among seizures even in a same infant.

Cerebral Cortex↗
PubMed1999

Elevated plasma levels of glucagon-like peptide-1 after oral glucose ingestion in patients with pancreatic diabetes.

OBJECTIVE: The purpose of the present study was to evaluate plasma glucagon-like peptide-1 (GLP-1) responses after oral glucose ingestion in patients with chronic pancreatitis and to clarify how GLP-1 secretion relates to pancreatic diabetes. METHODS: An oral glucose tolerance test (OGTT) was performed in 17 patients with chronic pancreatitis. Plasma glucose, immunoreactive insulin (IRI), C-peptide, glucagon, and GLP-1 levels at each time point during OGTT were measured. The diagnosis of chronic pancreatitis was made by the findings of endoscopic retrograde pancreatography (ERP): evident dilation of the main pancreatic duct with or without pancreatolithiasis. RESULTS: The patients were divided into three groups according to the World Health Organization classification of diabetes based on plasma glucose levels after OGTT. The groups were: normal (three patients), impaired glucose tolerant (IGT) (six patients), and diabetic (DM) (eight patients). In the DM group, IRI and C-peptide response levels after oral glucose ingestion were significantly reduced as compared with those of the normal and IGT groups. No significant glucagon responses to oral glucose ingestion were found in the three groups. In contrast, plasma GLP-1 levels were significantly elevated after oral glucose ingestion in the DM groups as compared with normal and IGT groups. CONCLUSIONS: The present study affords evidence that plasma GLP-1 levels become elevated with development of pancreatic diabetes, although the precise mechanism of this elevation remains undetermined.

C-Peptide↗
PubMed1999

[Leiomyoma of the lung: a case report].

An asymptomatic 43-year-old female was admitted to the Hospital because of an abnormal nodule in the left lung field on screening chest X-ray. Chest CT showed a tumor shadow mass (4 x 3 cm) in the left lower lobe. Bronchofiberscopy revealed an endobronchial polypoid mass obstructing the lower lobe bronchus at the orifice of left B10. Lt lower lobectomy was performed. Histopathological examination of the specimen showed the tumor (4.5 x 3.6 x 3.6 cm) developing not only within the tracheal lumen, but also in the lung tissue. Because immunohistochemical staining for desmin and alpha-smooth muscle actin was positive, we diagnosed leiomyoma. As MRI revealed multiple uterine masses after operation, we discussed the diagnostic problems in the relation to metastasizing leiomyoma of the uterus.

Adult↗
PubMed1999

[Connatal type of Pelizaeus-Merzbacher disease: a case report].

Pelizaeus-Merzbacher disease (PMD) is a hereditary disorder with myelin dysplasia in the central nervous system. The connatal type is a more severe form compared to the classical type and shows developmental arrest or deterioration, nystagmus, spasticity, and/or convulsions in the neonatal period. A 1 1/4-year-old Japanese boy diagnosed as connatal type PMD is reported here. Soon after his birth, he demonstrated horizontal and rotatory nystagmus and opisthotonic posture. At the age of 10 months, he had difficulty in feeding. At the age of 1 year, he presented more severe opisthotonic posture and frequent vomiting. He showed deterioration in gross motor development. His chromosome analysis showed a normal male karyotype. Electroencephalogram did not show a sleep spindle. Auditory evoked brainstem responses (ABR) showed only wave I on both sides. Visual evoked potentials (VEP) showed prolongation of latencies. These results were compatible with PMD. Nuclear magnetic resonance imaging (MRI) demonstrated in the white matter of cerebrum and brainstem no high intensities on T1-weighted images and diffuse high intensities on T2-weighted images. Such absence of myelination including the brainstem was characteristic to the connatal type PMD. The diffuse disturbance of myelination appeared to correlate with the severity of clinical symptoms.

Brain↗
PubMed1999

Proteolipid protein gene duplications causing Pelizaeus-Merzbacher disease: molecular mechanism and phenotypic manifestations.

Pelizaeus-Merzbacher disease (PMD) is an X-linked disorder characterized by dysmyelination of the central nervous system (CNS) caused by mutations involving the proteolipid protein gene (PLP). In addition to point and frameshift mutations in the coding region, duplications involving the entire PLP have been recognized recently as a major genetic abnormality causing PMD. We devised an interphase fluorescence in situ hybridization (FISH) assay to establish an efficient screening test for PLP duplication. Thirteen patients from 11 Japanese PMD families were determined to have PLP duplications. This molecular diagnostic FISH test also readily detected female carriers. Molecular analysis revealed that the size of the duplication and location of the breakpoints showed striking variation. Fiber FISH demonstrated that the duplication is tandem in nature. Haplotype analysis indicated an intrachromosomal origin for the duplication. These results suggest that an unequal sister chromatid exchange in male meiosis is likely to be the major mechanism leading to the formation of the duplication. Patients with the duplication commonly present with a mild PMD phenotype. Two patients with an exceptionally severe clinical phenotype carried large duplications, suggesting that either the larger duplicated segment incorporates additional dosage-sensitive genes or that the location of the duplication junction may affect the phenotype.

Adolescent↗
PubMed1999

[Location of primary somatosensory area in cerebral arteriovenous malformation involving sensorimotor area].

The purpose of this study was to investigate the cortical reorganization associated with congenital brain lesion such as intracerebral arteriovenous malformation (AVM). Dipole source localization of somatosensory evoked potential (SEP) was performed in five patients with AVM encompassing sensorimotor cortex. Dipole tracing method combined with the scalp-skull-brain head model (Homma et al., 1994) was used to locate dipole source of an early cortical component of SEP elicited by median nerve electrical stimulation. The location of dipole source of SEP, which could be considered as the hand area of primary somatosensory area, was shown in the realistic section of the head and could be easily superimposed on the magnetic resonance imaging. SEP was recorded three times in each patients and the results were reproducible. In 2 patients whose postcentral gyrus was not involved in AVM, the dipole source of SEP was localized in the intact postcentral gyrus. The locations of dipole sources of SEP in the both hemisphere were symmetrical. In 3 patients whose postcentral gyrus was encompassed by AVM, the dipole source of SEP was localized in the surrounding intact gyrus which was distant from the usual region of postcentral gyrus. Somatotopy was different from the normal pattern. The hand area was located more medially than usual observed in normal postcentral gyrus. Despite the paucity of the number of patients and data obtained by dipole source localization, our findings support the existence of reorganization in the cerebral cortex with congenital lesion such as AVM. These findings of aberrant mapping of cortical function may be explained by the plasticity of brain function. The developing brain can inherit function that would normally have been performed by the region of brain involved in the lesion. We demonstrated that dipole tracing of SEP was a noninvasive method used to localize areas of eloquent cortex in patients harboring AVM. This method is of value in treatment planning.

Adolescent↗
PubMed1999

Proton MR spectroscopy of Sjögren-Larsson's syndrome.

We performed single-voxel proton MR spectroscopy (1H-MRS) in two children with Sjögren-Larsson's syndrome (SLS). Both patients showed two abnormal spectral peaks at 1.3 ppm and 0.9 ppm that were obtained with short echo times. These two abnormal spectral peaks were seen in high-intensity areas on T2-weighted images and also in basal ganglia of normal intensities. 1H-MRS may be useful for establishing the diagnosis and investigating the natural history of SLS, and for evaluating the efficacy of therapeutic approaches to SLS.

Aldehyde Oxidoreductases↗
PubMed1998

The effect of volatile anesthetics on light-induced phosphorylation in spinach chloroplasts.

(1) The light-induced phosphorylation in spinach chloroplast is coupled with proton transfer. (2) We investigated the effect of volatile anesthetics (halothane, enflurane, isoflurane) on the cyclic and/or non-cyclic light-induced phosphorylation. (3) We used potassium ferricyanide as a Hill oxidant for non-cyclic phosphorylation and phenazin-methosulfate as an oxidation-reduction indicator for cyclic phosphorylation. (4) These three anesthetics inhibit the Hill reaction in light induced phosphorylation. The inhibition rate of this reaction generates concave curves with minimum values at 303 K in each of the anesthetics.

Anesthetics, Inhalation↗
PubMed1998

Characteristic MR features of encephalitis caused by Epstein-Barr virus: a case report.

An 8-year-old girl showed symptoms of encephalitis during acute Epstein-Barr virus (EBV) infection. The diagnosis of EB virus infection was made by changes in the titres of EB virus-specific antibody. Cranial MRI demonstrated abnormal low and high signal intensities in the striatal body (putamen and caudate nucleus) on T1-weighted and T2-weighted images, respectively, during the acute phase. These abnormal findings had almost completely resolved 1 month later. EBV infection should be considered when lesions are localised to the basal ganglia.

Caudate Nucleus↗
PubMed1998

Molecular cloning of the chromosomal breakpoint in the LIS1 gene of a patient with isolated lissencephaly and balanced t(8;17).

Karyotypic analysis of a patient exhibiting a phenotype of isolated lissencephaly, and of her parents, revealed a de novo balanced translocation, t(8;17)(p11.2; p13.3). Since the lissencephaly (LIS1) gene was known to be located on 17p13.3, we investigated whether the translocation might involve this gene. We performed Southern analysis using cosmid clones that contained genomic sequences corresponding to LIS1, and found that the breakpoint was located within intron 1. As sequence analysis of the parental chromosomes in the vicinity of the breakpoint identified no additional putative transcripts, haploinsufficiency of the LIS1 gene is likely to be solely responsible for the patient's lissencephaly. Characterization of both breakpoints indicated a possible involvement of repetitive sequences in the recombigenic process that led to the translocation.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1998

Alteration of the LIS1 gene in Japanese patients with isolated lissencephaly sequence or Miller-Dieker syndrome.

LIS1 is a genetic entity that is responsible for lissencephaly. Previously we have reported isolated lissencephaly sequence (ILS) in a Japanese patient carrying a balanced chromosomal translocation that disrupted the LIS1 gene. We examined mutations of LIS1 in 12 additional Japanese patients, 8 of them with ILS and 4 with Miller-Dieker syndrome (MDS). Fluorescence in situ hybridization (FISH) analysis disclosed deletions of part of the LIS1 gene or of the chromosomal region surrounding it in three of the ILS cases and in three of the MDS cases. In one of the remaining five ILS cases, SSCP analysis and subsequent sequence analysis identified a 1-bp deletion in exon IV, which can be expected to result in premature termination of the gene product. Our results indicate that in Japan, as elsewhere, abnormality of the LIS1 gene is a common cause of MDS/ILS.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗